Radeon hd 7970 or gtx 670?

With latest drivers amd hd 7970 is better than gtx 670.In real world performance both are same.both will maxout any games for next coming years.i would reccomend grab anyone which is at less price.

You can't go wrong with either. They both perform exceptionally good at 1080p.

If you want high overclocking headroom and more VRAM, get the HD7970.

If you're concern about power usage, wants features like PhysX, Adaptive Vsync and TXAA, get the GTX 670.

A comparison of the two: http://www.anandtech.com/bench/Product/508?vs=598

to be honest i never used a nvdia card before. does Physx improve gaming performance?

Yes it improves.Main benifit of getting nvidia is physicx,adaptive vsync and most games support nvidia well.